DescriptionAtelopus longirostris is distinguished easily from A. lynchi and A. carauta by having discrete yellow spots on the dorsal surfaces, and an elongate marking behind each eye. A. longirostris has a long, narrow snout, more so than that of A. lynchi (see Cannatella 1981, p. 137). The tip of the snout is not curved in A. longirostris, as it is in A. carauta (where it is curved toward the venter). The canthus is distinctly concave in A. longirostris but straight in A. carauta and A. lynchi (Cannatella 1981).

Atelopus longirostris occurred on the north-west side of the Ecuadorian Andes from the Provinces of Esmeraldas, Imbabura, Cotopaxi and Pinchincha, at elevations from 200 to 2,500 m a.s.l. Its main habitat was montane and lowland tropical rainforest (Stuart et al 2008).

Life History, Abundance, Activity, and Special BehaviorsThis species bred in streams (Stuart et al 2008).

Trends and ThreatsThis species was last recorded from Ecuador in 1989, and is now considered extinct after twenty years without a sighting, despite extensive searches. The cause of extinction has not been determined, but possibilities include the disease chytridiomycosis, climate change, pollution, and habitat destruction. Chytridiomycosis is believed to have been a factor in extinction, as for many species of Atelopus, but this is uncertain; A. longirostris occurred at lower elevations where this disease has not previously been considered to be a threat. Its range lay partly within at least one protected area, the Reserva Ecológica Cotacachi-Cayapas and may have extended to the northern limit of the Reserva Ecológica Los Illinizas (Stuart et al 2008).

CommentsThe type specimen was described by Cope (1868) but has apparently been lost (Peters 1973). A. longirostris has been confused with other species (A. coynei, A. carauta, A. lynchi); specimens from Colombia in particular belong to a different species (Peters 1973; Lötters 1996). Cannatella (1981) has described specimens from northern Ecuador and southern Colombia as a new species A. lynchi, rather than A. longirostris, and pointed out that some Ecuadorian Atelopus specimens tentatively assigned to A. longirostris (Peters 1973) are in fact A. coynei.

The genus Atelopus, found in Central and South America, has experienced dramatic declines due to amphibian chytrid fungus. Of 113 described and putative species, at least 30 species appear to be extinct, having been missing from all known localities for at least 8 years (La Marca et al. 2005). Only 52 of the surviving species have sufficient data with which to evaluate population trends; of these, 81% (42 of 52) have population sizes that have been reduced by at least half (La Marca et al. 2005). Only 10 of the 52 species appear to have stable populations (La Marca et al. 2005). Higher-elevation species (those living at least 1000 m a.s.l.) have been hit the worst, with 75% (21 of 28) having disappeared entirely (La Marca et al. 2005).

Most Atelopus species are restricted to very limited areas (no more than two localities) and occur along mid- to high-elevation streams (1500-3000 m a.s.l., though the maximum vertical range is from sea level to permanent snow; Lötters 2007), a habitat preference frequently associated with the co-occurrence of chytridiomycosis (La Marca et al. 2005). Habitat loss has occurred within the ranges of many Atelopus species, but does not appear to be a major factor in the decline of most Atelopus species; 22 species declined despite occurring in protected areas (La Marca et al. 2005). Many Atelopus species are local endemics, putting them at particular risk of extinction, with at least 26 species known only from a single population inhabiting a narrow altitudinal range (La Marca et al. 2005).